Single-carrier impact ionization favored by a limited band dispersion

TL;DR

This paper proposes that materials with limited band dispersion, like certain chalcogenides, can enable single-carrier impact ionization, which is crucial for high-performance avalanche photodiodes, by restricting carrier kinetic energy.

Contribution

It introduces the concept that limited band dispersion in specific materials facilitates single-carrier impact ionization, a novel approach for photodiode design.

Findings

Limited band dispersion restricts carrier kinetic energy.

Chalcogenides exhibit the desired band structure.

Potential for high-gain, low-noise avalanche photodiodes.

Abstract

A critical requirement for high gain and low noise avalanche photodiodes is the single-carrier avalanche multiplication. We propose that the single-carrier avalanche multiplication can be achieved in materials with a limited width of the conduction or valence band resulting in a restriction of kinetic energy for one of the charge carriers. This feature is not common to the majority of technologically relevant semiconductors, but it is observed in chalcogenides, such as Selenium and compound I2-II-IV-VI4 alloys.